EP 14159337 A1 describes a device and a method for remote maintenance of an elevator installation, which device is installed at the elevator installation and receives first signals from a sensor of the elevator installation, for example from an acceleration sensor. The device converts received first signals into second signals and passes on these second signals for evaluation to a remote maintenance center by way of a telecommunications network.
WO0200702030322A1 describes a further device and a further method for the positioning of an elevator installation, in that a first acceleration sensor is placed on a car and an additional acceleration sensor is placed on a car door, which allows for an independent determination of acceleration of the car and of acceleration of the car door. The positions of the car and the car door are determined through a double integration of the accelerations.